The use of carrier matrices to promote the formation of bone at a site in a patient is well known, and related products are currently available on the market, such as Mastergraft® Putty and Mastergraft® Matrix, both by Medtronic Sofamor Danek (Memphis, Tenn.). These matrices are typically in the form of a relatively large, soft collagen sponge or dry cake that is wetted and then packed into the bone defect.
A significant problem associated with bone regeneration when using such matrices is the lack of a suitable scaffolding material that can retain its shape and stay within the bone defect during the healing process but which is also compatible with the body. Accordingly, there is a need for improved bone graft substitutes for the repair of bone defects that are capable of retaining their shapes as new bone is generated of sufficient volume within the bone defect.